1、情态动词,中考情态动词主要以单项选择和填空形式为主,要求考生掌握不同的意义和用法。,常用的情态动词有: can,may,must,need, shall, should, had better 1. can 的用法: 表示能力 “能,会” He can speak a little Japanese. 表示请求或许可 “可以” Can I have a look at your photos?You can go now. 表示猜测 “可能” Where can she go now? 她可能到哪里去了呢?,注: 1)could是can 的过去式,也可表委婉的请求,如Could you ple
2、ase close the window? 2)can和be able to表能力时的区别。 can只用于现在时,表一般具有的能力。 be able to可用于各种时态,常指通过努力最终做成某事,表在特定条件下的能力。 如:Although the driver was badly hurt, he was able to explain what had happened.We were able to arrive there on time at last. (表示过去成功完成的事),2.may 的用法: 表示请求或允许 “可以,准许” May I go home,please? 表示可
3、能性 “ 可能”、也许” 只用于肯定句和否定句中。 I think it may rain this afternoon. He may not be right. 注:might为may的过去式,但也可以代替may,语气较为婉转客气或更加不肯定。 He might not come today. 今天他也许不来了。(语气不肯定)You might also get a headache when you work too hard. 当你工作太努力时, 你也可能患头痛。,注意: may be和maybe. 二者都表示推测,意为“可能、也许”。 1)may be为情态动词动词原形,用于句中作谓
4、语,如:That may be your teacher. 2)maybe为副词,相当于perhaps,用于句首作状语,如:Maybe you are a teacher.,3. must的用法: 表示义务、必要或命令 “必须、应该”(must表示主观看法,have to强调客观需要。)You must come early tomorrow Its too late, I have to go home now. 注意: must开头的疑问句,其否定回答通常用dont have to 或neednt ,而不用mustnt 。mustnt表示禁止,不许 -Must I finish my ho
5、mework first? -No, you dont have to/ neednt., 表示推测,“肯定,一定”, 否定形式用cant. They must be at home. The light is on. It can not be Li Lei. 那个人不可能是李磊。It must be Li Lei. 那个人肯定是李磊。,4. need 的用法: 情态动词 “需要, 有必要”一般用于否定句或疑问句中。You neednt come here this afternoon. 实意动词 “需要, 有必要” 可以用于各种句式中。 You dont need to go now. 你
6、不必现在就走。 I need to have a rest. 我需要休息一下 Do we need to finish all the work today? 我们今天需要完成所有的工作吗?,注: 1)可用作情态动词或实义动词的有need,dare。作情态动词时多用于否定句和疑问句中,后接动词原形;作实义动词时有人称、数和时态的变化, 后接动词不定式to do。 -Need I go now? -Yes, you must./No, you neednt. He needs to study harder.(实义动词) Dare he tell them the truth?(情态动词),2)
7、可作情态动词也可作助动词的有will, would, shall, should。 will表询问、请求或意愿We will go camping tomorrow.(表意愿,作助动词) Will you lend me your book? would表过去的意愿或委婉的请求Would you tell me the time? shall用于第一人称表示征求意见Shall we begin now? 拓展:shall用于二、三人称陈述句,表说话人命令、警告、允诺、威胁等口吻 如: You shall fail if you dont work harder. should “应该”用于表示
8、义务和责任You should keep the room warm.,情态动词表推测小结: 1)肯定句中表推测“可能”:can,could,may,might都可以在肯定句中表“可能”。其中can的语气最强,可能性最大,其余依次递减。 肯定句中表推测“一定,肯定”用must. 2)疑问句中表推测“可能”:用can,could,might,而不能用may. mustnt 不表示推测,而表示禁止。 意义为“禁止,不准” 3)否定句中表推测: may not/might not:可能不 can not/could not: 不可能 eg: You may not be right你也许不对. Yo
9、u can not be right你不可能对.,练习题,1.(2003天津)You _go and ask Meimei. She_know the answer . A.must ,can B.must ,may C.need ,can D.can, may 2.(2003福建福州)-Must I stay at home, Mum? -No ,you_. A.mustnt B.may not C.cant D.dont have to 3.(2003广东广州)The boy said he had to speak English in class ,but he_speak it af
10、ter class . A.could B.didnt have to C.might D.shouldnt,4.(2004江苏苏州) Could you tell me if he_finish the work on time ? A.could B.was able to C.is able to D.would be able to 5.(2004上海) We_ keep the new traffic law and learn how to protect ourselves . A.may B.should C.can D.need 6.(2004广东佛山) -What a ni
11、ce day! _we go surfing ? -Good idea ! A.Shall B.Must C.Can D.Need,7.(08福建福州) -Kate,_you dance the disco?-Yes, I can. A. may B. can C. must D. need 8.(08重庆) -Whos that boy reading in the garden?Is it David? -It_be David. I saw him in the classroom just now. A. must B. cant C. may D. should 9.(08河北)Th
12、omas, Please be quiet. The others_hear very well. A. cant B. mustnt C. shouldnt D. neednt,10.(2010呼和浩特) -Mom, may I go out to play now? -Yes, you can. But your homework_first, I think. A. has to finish B. must finish C. finished D. must be finished 11.(2010重庆) -Must I clean the room now? -No, you_. You can do it tomorrow. A. mustnt B. must C.neednt D.need,